phase 1c-extract: typed kRPC service client + SpaceCenter extract

Built the missing piece that connects the ksp-bridge to a real KSP
instance via kRPC. This adds a typed service client on top of the
existing KRPCClient, plus the SpaceCenter-specific extraction logic
that pulls the universe state from a running KSP save.

@kerbal-rt/krpc-client
- types.ts — runtime representation of kRPC Type descriptors
  (TypeCode enum, KrpcType interface, decodeKrpcType, typeName)
- decoder.ts — kRPC value codec: primitive decode/encode, class refs,
  enums, collections (LIST/SET/TUPLE/DICTIONARY), system messages
  (STATUS/SERVICES/STREAM/EVENT/PROCEDURE_CALL). 34 unit tests.
- services.ts — ServiceCache built from KRPC.GetServices() response.
  Lookup by (service, procedure), enum value/name resolution. 12 tests.
- service-client.ts — KrpcServices: high-level invoke-by-name client.
  loadServices() helper to connect + load catalog. 9 integration tests
  with a mock kRPC server.
- schema.ts — added Set/Dictionary/Event/Expression types so the
  decoder can handle system messages without external .proto files.
  Also fixed a bug where 'STREAM' was being encoded as 0 due to
  protobufjs's nested-enum string lookup.

ksp-bridge
- extract.ts — the actual SpaceCenter calls. ~280 procedure calls
  per poll for a typical KSP save (UT, bodies, vessels, then per-body
  and per-vessel class methods in parallel). Build the UniverseSnapshot.
- krpc-adapter.ts — rewrote to use KrpcServices (typed) instead of
  the stub extract function. Supports an optional injected services
  for testing.
- bridge.ts — uses the new ExtractedState type and buildSnapshot.
- index.ts — connects to kRPC; falls back to mock mode if no server.
- convert.ts — backward-compat shim, re-exports from extract.ts.

The ksp-bridge can now talk to a real KSP install. We do NOT need
the kRPC mod's .proto files on disk — the server's GetServices()
response is the source of truth for type info. Documented the full
list of procedures we call, the kRPC value encoding, and the new
architecture in ksp/README.md.

Tests: 119 total, all green. Typecheck and build clean across all 11
projects.

Bonus: fixed an integer-overflow bug in the krpc-client connect()
handshake (was passing 'RPC'/'STREAM' strings to protobufjs; its
nested-enum string lookup silently encodes as 0, which made the
stream handshake send the wrong type. Switched to numeric codes.)

packages/krpc-client/src/index.ts

@@ -7,10 +7,16 @@
  *  - sendMessage / recvMessage / recvRawMessage / encodeVarint / decodeVarint:
  *    low-level wire-format helpers
  *  - KRPC namespace: protobufjs types for the kRPC meta-protocol
+ *  - KrpcType / TypeCode: runtime representation of kRPC type descriptors
+ *  - decodeValue / encodeValue: kRPC value codec (primitives, classes,
+ *    enums, collections, system messages)
+ *  - ServiceCache: a Type index built from KRPC.GetServices()
+ *  - KrpcServices: high-level invoke-by-name client
  *
- * See ./schema.ts for the meta schema. The service-specific types
- * (SpaceCenter.Vessel, Orbit, etc.) need to be loaded from the kRPC
- * mod's .proto files at runtime when running against a real KSP.
+ * For the service-specific types (SpaceCenter.Vessel, Orbit, etc.) we do
+ * NOT need to load the kRPC mod's .proto files. The server's
+ * GetServices() response contains everything we need to encode/decode
+ * values. See ./service-client.ts for the details.
  */
 export {
   KRPCClient,
@@ -26,4 +32,27 @@ export {
   decodeVarint,
   tcpConnect,
 } from './connection.js';
-export { KRPC, encodeMessage, decodeMessage } from './schema.js';
+export { KRPC, encodeMessage, decodeMessage, MESSAGE_TYPES } from './schema.js';
+export {
+  TypeCode,
+  decodeKrpcType,
+  typeName,
+  type KrpcType,
+  type TypeCodeValue,
+  type RawKrpcTypeMessage,
+} from './types.js';
+export {
+  decodeValue,
+  encodeValue,
+  decodeDouble,
+  decodeFloat,
+  decodeSint32,
+  decodeUint32,
+  decodeUint64,
+  decodeBool,
+  decodeString,
+  decodeBytes,
+  type DecodedValue,
+} from './decoder.js';
+export { ServiceCache } from './services.js';
+export { KrpcServices, loadServices, type KrpcInvokeError } from './service-client.js';